梨果柄特征及其与果实主要经济性状的相关性分析

为了解梨果柄生长发育对果实品质的影响,该试验以11个梨品种为材料,对果实主要经济性状、可溶性糖、矿质养分等进行了测定分析,并对果柄显微组织结构进行了解剖观察。结果显示：(1)梨不同品种间果柄形态及显微结构存在明显差异,大果型品种果柄内有10个维管束,中果型品种有9个维管束,小果型品种有5个维管束。(2)大果型砂梨品种中,果柄横截面维管束占比越高,单果重越大。(3)梨果柄粗度与果实大小之间存在显著相关关系,且相关性大小表现为白梨大于砂梨。(4)同一梨品种的中果柄和粗果柄果实的可溶性总糖含量显著高于细果柄果实。(5)果柄粗度影响果实果肉矿质养分含量,‘秋月’的中果柄和粗果柄果实的Ca和B含量显著优于细果柄果实,且中果柄果实的含量最高。研究表明,梨不同品种的果柄形态结构不同,且果柄发育状况影响果实生长发育,尤其果柄粗度是限制果实大小和影响果实品质的重要因素之一;同一梨品种的中果柄果实品质优于粗果柄和细果柄果实。     

不同基因型梨木质素代谢对石细胞含量和果实口感的影响

以五种基因型梨果实为材料,对石细胞团的大小、分布进行解剖学观察,并测定石细胞、木质素含量和木质素相关合成酶PAL、POD、PPO活性,探讨不同基因型梨果实木质素代谢对石细胞含量及口感的影响.结果表明,不同基因型梨木质素含量高时,石细胞含量也高,石细胞团相对较大,分布较密集,口感差.各基因型的梨木质素、石细胞含量和大小为...     

单宁细胞形态与部分柿属种及品种相关性研究

采用软柿果肉直接压涂法,在光学显微镜下对204个柿属种及品种果实中的单宁细胞形态特征进行观察分析.结果显示:(1)在6个种柿属植物果实中,均含有单宁细胞,其外形大多属于短形和近圆形,但在数量、大小和颜色上存在差异,其中,油柿(Diospyros oleifera Cheng.)、君迁子(D.lotus Linn.)、柿(D.kaki Thunb.)、浙江柿(D.glaucifolia Metc.)的单宁细胞通常无色,而黑柿(D.nitida Mcrr.)为黄绿色,乌材(D.eriantha Champ.)为紫红色,乌柿(D.eathayensis Stheward.)为淡紫色;单宁细胞从大到小依次为油柿>君迁子>浙江柿>乌材>黑柿>乌柿.(2)单宁细胞在不同品种类型间差异明显,其中涩柿单宁细胞多为无色,单宁细胞比较宽大;甜柿品种均会出现褐变的单宁细胞,单宁细胞较小或瘦长;完全甜柿品种大多存在着凝固型褐变单宁细胞,仅少数凝聚呈球形,且单宁细胞分散存在于果肉中,果肉中的褐斑较细小;不完全甜柿在种子周围的褐斑处,可以看到大量的表面凹形且褐变的收缩型单宁细胞,且常以单宁细胞束的形态存在于果肉中,使果肉中的褐斑大而密;原产我国的完全甜柿中不存在凝聚型的单宁细胞,只有凝固型的单宁细胞.(3)聚类分析结果表明,单宁细胞的特征可以作为不同类型柿属种的分类依据.     

‘黄金梨’果肉硬化症的果实显微结构观察

本文以‘黄金梨’硬化症病果和正常果为试材,采用常规的石蜡切片法,比较了硬化症病果果肩部（SE）、果顶部（CE）以及正常果果肩部（CKSE）和果顶部（CKCE）的表皮及果肉的解剖结构差异。结果表明,CKSE和CKCE的角质层薄,随表皮细胞的生长出现不同程度的起伏,单宁细胞层平均为3-4层;SE和CE的角质层和单宁细胞层细胞相对较厚。‘黄金梨’的表皮层和单宁细胞层细胞的横径长度均大于纵径,但CE和SE的纵／横比值均高于CKSE和CKCE,说明病果的细胞形状发生了变化,逐渐接近于圆形或椭圆形,尤其是硬化症症状严重的果顶部。果肉硬度大小依次是CE〉SE〉CKCE〉CKSE：CKCE、CKSE和SE果肉中石细胞团直径较CE大;CKSE和CKCE的团围薄壁细胞的长度比SE和CE的长。     

梨贮藏过程中乙烯和钙调素动态及其与贮藏性的关系

对两个梨品种不同成熟期果实贮藏过程中,整个果实以及果皮、果肉、果心的乙烯释放变化及果肉、种子的钙调素(CaM)含量进行测定。结果表明:(1)黄花品种完整果实及不同部位乙烯释放量都高于耐贮藏的湘南品种,且启动乙烯生成和形成乙烯峰值的时间也早于湘南品种;(2)果实不同部位形成峰值的顺序均依次为果心、果肉、果皮;(3)果实呼吸跃变过程中,CaM含量伴随乙烯释放量的上升而升高,乙烯峰值过后,CaM含量下降,果实衰老。     

黄瓜叶表面特性与生态适应性

对不同类型的黄瓜品种的气孔形态进行了扫描电镜观察 ,发现需水量不同的黄瓜品种气孔形态特征有很大的差异。保卫细胞表观差异比较明显 ,气孔的密度、大小及开张度均有显著的差异 :亚洲类型的黄瓜品种气孔密度较欧洲类型与欧亚杂交品种大 ,气孔的保卫细胞的大小为欧洲品种 >欧亚杂交品种 >亚洲品种。气孔周围的形态特征表现为 :亚洲品种保卫细胞角质褶皱较多 ,起伏较大 ,气孔深深地陷于褶皱中 ;欧洲品种黄瓜气孔保卫细胞周围角质则较平坦 ,保卫细胞突出于表皮细胞之上 ;欧亚杂交品种的气孔大小与形态介于上述二者之间。土壤含水量的不同也影响黄瓜叶片气孔的形态特性 ,随着土壤含水量的减少 ,黄瓜叶片单位面积的气孔密度增加 ,保卫细胞的大小变小 ,气孔开展度增加。     

不同黑莓品种果实形态和硬度分析及其解剖结构和微形态特征观察

以3个黑莓(Rubus spp.)品种‘Arapaho’、‘Boysenberry’和‘Kiowa’的成熟果实为实验材料,对果实的形状指标以及硬度进行了测定,并采用石蜡切片技术和扫描电子显微镜分别对3个品种果实的解剖结构以及外果皮及果肉的微形态特征进行了观察;在此基础上,对果实结构与果实硬度的关系进行了探讨.结果表明:品种‘Arapaho’果实的硬度值(0.79 lb·mm-2)大于品种‘Boysenberry’和‘Kiowa’果实的硬度值(0 lb·mm-2):品种‘Arapaho’果实的纵径、横径和单果质量均极显著小于‘Boysenberry’和‘Kiowa’果实.石蜡切片观察结果显示:3个品种的外果皮均较薄且无角质层覆盖,由1～2层表皮细胞组成;其中,品种‘Arapaho’果实的表皮细胞1层、短小且排列紧密,品种‘Boysenberry’果实的表皮细胞2层、细长且排列疏松整齐,品种‘Kiowa’果实的表皮细胞2层、胞壁有褶皱且果面局部凹陷.品种‘Arapaho’的中果皮由大量较完整的薄壁细胞组成并包含没有解体的维管束,而品种‘Boysenberry’和‘Kiowa’的中果皮内均匀分布着解体的薄壁细胞.扫描电镜观察结果显示:品种‘Boysenberry’外果皮具浅波状纹饰、表皮细胞形状不规则,并具稀疏的表皮毛和片状分泌物;品种‘Kiowa’外果皮表面有明显的不规则波纹状纹饰;品种‘Arapaho’外果皮表面纹理紧凑致密、表皮细胞轮廓清晰且形状规则.3个品种的果肉细胞均呈现不同程度的解体现象,但品种‘Arapaho’的果肉细胞中分布有没有解体的胶状物质.根据观察结果推测:黑莓果实果皮和果肉的解剖结构以及微形态特征与其硬度有一定的关系.     

套袋黄冠梨果实花斑病发生与其组织结构变化的关系

以黄冠梨果实为试验材料,在调查套袋处理果实花斑病发生的基础上,研究了套袋及未套袋黄冠梨果实发育过程中的组织结构变化,并分析了发病果实的病部与正常果实组织结构差异。结果显示:(1)套3层袋果实花斑病的发病率为22.5%,而不套袋果实的发生率仅为1.5%。(2)未套袋果实角质层厚,而且呈波纹状分布,并渗入到表皮细胞间隙中,果实发育过程中厚度变化幅度不明显;套袋果实表面的角质层均匀一致,随果实迅速膨大,角质层变薄,且显著薄于未套袋果实,尤其是套3层袋与未套袋果实差异更大;套袋果实表皮细胞呈长方形,且较未套袋果实排列致密;不同套袋处理果实单宁细胞层数随果实发育逐渐减少,在花后90 d后,套袋处理与未套袋处理的厚度无显著差异。(3)套袋果实果肉薄壁细胞排列紧密,胞间隙小,其石细胞大小和密度均较未套袋果实小。(4)套袋果实花斑病发病部位角质层模糊,发病果实正常部位的角质层、表皮层厚度和单宁层均低于正常果实。研究表明,套袋黄冠梨果实表面组织结构发生较明显变化,它对梨果实花斑病的发生有重要影响。     

套袋苹果果实质地及其显微结构与果面裂纹的关系北大核心CSCD

以套白色单层纸袋的着色富士系‘天红2号’和短枝富士后代优系4-1-103,以及不着色姊妹系‘冀苹4号’和‘冀苹5号’4个苹果品种(系)为试验材料,利用质构仪整果穿刺和质地多面分析法(texture profile analysis,TPA)测定果实质地,光学显微镜观察果实显微结构,探讨苹果果实质地及其显微结构与果面裂纹的关系,为抗裂纹品种的选育和潜在裂纹机制提供理论依据。结果表明:(1)盛花后132~185 d,‘天红2号’和‘冀苹4号’裂纹率和裂纹指数始终高于4-1-103和‘冀苹5号’,其裂纹主要部位为果肩部。(2)‘天红2号’和‘冀苹4号’的果肉脆裂性、果肉硬度分别显著小于4-1-103和‘冀苹5号’。(3)‘天红2号’和‘冀苹4号’的表皮细胞密度显著小于4-1-103和‘冀苹5号’,其果肉细胞间隙率显著大于4-1-103和‘冀苹5号’,且其角质膜有“V”型凹陷,并发生龟裂,而4-1-103和‘冀苹5号’角质膜完整均一。(4)主成分和灰色关联度分析表明,果肉硬度、果皮果肉硬度比和果肉细胞间隙率是解释裂纹的主要指标。研究发现,果实角质膜完整均一、果肉硬度大、果肉细胞间隙率小的苹果品种不易发生果面裂纹。     

罗汉果果肉中糖类物质组成与含量分析

罗汉果果实中富含糖分,糖类物质的组成及其含量对果实的内在品质有重要影响,然而多年来对其品质的研究多集中在罗汉果苷上,果实中可溶性糖种类与含量迄今尚未见有系统地报道。该研究以干燥的罗汉果果实为材料,采用PMP柱前衍生化一高效液相色谱紫外检测法、高效液相色谱示差折光检测法分别检测果肉中可溶性糖的种类与含量,并进行方法学考察。结果表明:PMP柱前衍生化一高效液相色谱紫外检测法只能检出罗汉果果实中存在的2种还原性醛糖——葡萄糖、甘露糖;而高效液相色谱示差折光检测法则可一次性检出葡萄糖、果糖、蔗糖、棉籽糖、多糖5种糖分。与柱前衍生化法相比,高效液相色谱示差折光检测法更适合用来全面分析罗汉果果实中糖分的种类和含量。不同罗汉果品种果实中糖的组分一致,但含量有显著差别。另外,样品的干燥方式会影响果实中的总糖及各组分的相对含量。冻干果肉中蔗糖和葡萄糖相对含量最高,烘干则导致蔗糖和葡萄糖下降,果糖与多糖相对含量增加。     

Characteristics of the membranes of the pellicle of the ciliatePseudomicrothorax dubius

Summary The membranes of the pellicle of the ciliatePseudomicrothorax dubius are investigated using thin section electron microscopy and freeze-fracture replicas. The plasma membrane is covered by a surface coat and is connected to the outer alveolar membrane by short, sometimes branched, bridges. The inner alveolar membrane is coated on both sides. The epiplasm lies in intimate contact with the cytoplasmic surface of this membrane, and there is a corresponding deposit on the other surface. This deposit is regularly striated.The epiplasmic layer and the alveoli are interrupted at sites of cytotic activity,e.g., the attachment sites of trichocysts, the cytoproct, and the parasomal sacs. The striated deposit ends where the epiplasm ends, indicating a direct relationship between these two epimembranous layers.There is a deposit along the sides of the first part of the tip of the trichocysts, and in this region the trichocyst membrane is free of intramembranous particles.The membrane of the parasomal sacs has a coat on both surfaces. That on the extraplasmic surface is similar to the surface coat of the plasma membrane. The origin of the cytoplasmic coat is unknown. The cytotic activity of these sacs is indicated by their highly irregular profiles.     

The early development of the tail and the transformation of the shape of the nucleus of the spermatid of the domestic fowl,Gallus gallus

Summary The differentiation of the spermatid, especially in reference to the formation of the flagellum, and transformation of the shape of the nucleus was investigated in the domestic fowl.In the early stage of the spermatid, a prominent Golgi apparatus appears around the centrioles. The Golgi vesicles then surround the axial-filament complex which develops from the distal centriole. These vesicles fuse to form continuous membrane at the earliest stage of flagellar formation, and in the succeeding stage Golgi lamellae are attached to the plasma membrane of the developing flagellum. From these observations, it is assumed that Golgi apparatus may be a source of the membrane system of the flagellum.The microtubules distributed around the nucleus form the circular manchette. The anterior region of the nucleus with the manchette is cylindrical in shape and the posterior region without it remains irregular in shape. When the circular manchette has been completed, the whole nucleus acquires a slender cylindrical shape. The circular manchette then changes into the longitudinal manchette. The nuclei of spermatids without a longitudinal manchette are abnormal in shape. In view of these observations it is assumed that the nuclear shaping of the spermatid may be accomplished by circular manchette and the maintenance of shape of the elongated nucleus by longitudinal manchette.The authors wish to thank Mr. Takayuki Mori for his helpful suggestions and technical advices     

Characterization of the composition of the aqueous humor and the vitreous body of the eye of the frog Rana temporaria L

This study aimed to analyze the aqueous humor (AH) and the vitreous body (VB) of the eye of the adult frog Rana temporaria L. as a representative species of amphibians, which lead a semi-terrestrial life. The presence of collagen, albumin, uric acid and electron donors was shown in both media; however, there are slight differences in their concentrations. To determine collagen, a spectral-fluorescent probe, cyanine dye, was used. The presence of collagen in AH of the frog was found at the first time. The total content of electron donors (ascorbic and uric acids, tryptophan, and tyrosine) in VB and HA was roughly estimated at ~ 1.5 × 10^− 4 mol/L. Both VB and AH absorb light in similar UV regions. The total protein and albumin contents in AH were found to be somewhat higher than those in VB. The uric acid content was at an equally low level in both intraocular media. It is supposed that the similarity of VB and AH compositions shown in this work is due to some exchange between VB and AH contents in the course of accommodation. The role of intraocular fluids in physiological functions of the eye and in protecting the retina against UV light is discussed.     

Observations on the permeability of the choriocapillaris of the eye

Summary The choriocapillaris is a fenestrated capillary bed located posterior to the retinal pigment epithelium. It serves as the main source of supply to the photoreceptors, retinal pigment epithelium, and other cells of the outer retina. The permeability of these capillaries to intravenously injected ferritin (MW — approx. 480,000; mol. diam. 11 nm) was examined in the mouse, rabbit, and guinea pig, each of which is characterized by a different type of retinal vascularization. In all three species, the bulk of the ferritin remained in the capillary lumina, where it appeared to be blocked at the level of the diaphragmed fenestrae. Some ferritin was present in endothelial cell vacuoles. The results confirm previous work on the rat choriocapillaris and indicate that the barrier function of the choriocapillary endothelium is present even among species in which the retinal circulation differs significantly.Supported by NIH grant EY03418